Cellulitis vs Erysipelas

Skin Structure and Function

• The skin is the largest organ of the body, maintaining homeostasis, protecting underlying tissue and organs, and shielding against mechanical injury, damaging substances, and UV rays.
• The skin consists of three layers: epidermis, dermis, and hypodermis.
• The epidermis provides a waterproof barrier and determines skin tone.
• The dermis contains tough connective tissue, hair follicles, and sweat glands.
• The hypodermis is composed of connective tissue, fat, and other tissues.

Staphylococci

• Mode of transmission: direct contact with infected individuals, contaminated healthcare workers, and fomites like bed linens.
• Clinical findings: folliculitis, a common skin condition characterized by inflamed hair follicles, typically caused by bacterial or fungal infections.
• Pseudofolliculitis barbae (razor bumps) is a condition where tightly curled hairs embed into the skin, causing raised, reddened papules or pustules.
• Treatment: allowing hair to grow out, using hair growth inhibitors.
• S. aureus is susceptible to oxacillin, a penicillin-derived antibiotic.
• Patient care: use standard precautions for minor skin, burn, and wound infections, and contact precautions for major infections.

Other Bacterial Skin Infections

• Staphylococcus epidermidis: a part of the skin's normal flora, frequently linked to "stitch abscess," UTI, and endocarditis, and causes infections in people with prosthetic equipment.
• Streptococcus pyogenes: a Gram-positive, aerotolerant bacterium that produces enzymes and toxins responsible for pathogenesis, transmitted through direct contact with infected individuals or fomites.
• Erysipelas (St. Anthony's fire): an acute infection characterized by a skin rash, may refer to ergotism, a result of long-term ergot poisoning.
• Cellulitis: a common bacterial skin infection causing redness, swelling, and pain, can spread and cause serious health problems if untreated, and is preventable through good wound care and hygiene.
• Necrotizing fasciitis: a rare, deadly infection of the skin and tissues, characterized by rapid spread, tissue death, and aggressive progression.

Clinical Features and Complications

• Erysipelas: abrupt onset with fever, bright red skin, and a well-defined border.
• Cellulitis: low-grade fever, spreading, hot, tender plaque, dull red skin, and a less well-defined border.
• Necrotizing fasciitis: complications include acute glomerulonephritis, nonsuppurative, immune-mediated complications, and skin infections.

Pseudomonas aeruginosa

• A heterotrophic, motile, Gram-negative, rod-shaped bacterium that grows via aerobic and anaerobic respiration.
• It is a facultative anaerobe that can cause infections, especially in people with compromised immune systems.

Learn about the differences between cellulitis and erysipelas, two types of skin infections. Explore the symptoms, onset, and characteristics of each condition to better understand how to differentiate between them.